Occasionally in science, we get results that just make sense; this is one of those stories. Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) have found that not only do large stars tend to form more large planets than small stars, but you can see these future giants as large gaps in planet-forming disks. 

In this study, which is published in The Astrophysical Journal and led by Nienke van der Marel, researchers looked at more than 500 young stars. Van der Marel explains: Higher mass stars have relatively more disks with gaps than lower mass stars, consistent with the already known correlations in exoplanets, where higher mass stars more often host gas-giant exoplanets. These correlations directly tell us that gaps in planet-forming disks are most likely caused by giant planets of Neptune mass and above. Lower mass stars have more rocky Super-Earths—between an Earth mass and a Neptune mass. Disks without gaps, which are more compact, lead to the formation of Super-Earths.

So there you have it – giant stars with bigger disks form more and larger planets. Just this once, the universe makes sense, and it kind of feels like physics threw us a freebie.

More Information

NRAO press release

“A stellar mass dependence of structured disks: a possible link with exoplanet demographics,” Nienke van der Marel and Gijs Mulders, to be published in The Astronomical Journal (preprint on arxiv.org)